Optimal scintigraphic evaluation of a hydronephrotic horseshoe kidney

A 25-y-old man with horseshoe kidney was referred for diuretic-augmented renal scintigraphy. Single-detector dynamic posterior imaging was performed and revealed asymmetric retention of radiotracer in the left collecting system. Renal scintigraphy was repeated with a modified protocol. Dynamic imaging was performed this time using dual-detector acquisition of both anterior and posterior data. Thereafter, pregravity and subsequently postgravity static images were obtained in both anterior and posterior projections. This second study showed near-complete emptying of the left collecting system. This case illustrates the utility of using simultaneous anterior and posterior imaging and geometric mean calculations for functional analysis and also highlights the value of physiologic maneuvers to augment the traditional diuretic challenge.     

Epinephrine renal venography in acute bacterial infection of the kidney.

Epinephrine renal venography was performed in four cases of acute bacterial infection of the kidney. Selective renal arteriography was relatively nonspecific, while venography proved to be more helpful in excluding a malignancy. In cases of renal infection where the venous system of the kidney has not been occluded, epinephrine renal venography delineates the extent and nature of the process better than arteriography. Diffuse attenuation or smooth segmental narrowing of intrarenal veins, absence of irregularly encased veins, and veins draped around, as well as perforating, the abnormal region differentiated tumor from infection. An accurate diagnosis is important in view of the different therapeutic approach to these two entities.     

Supranormal renal function in unilateral hydronephrotic kidney can be avoided

INTRODUCTION: There are reports and controversy in the literature of supranormal (defined as >55%) differential renal function (DRF) in the hydronephrotic kidney in children with unilateral hydronephrosis. It is not confirmed whether supranormal DRF is an artifact or a true finding. In patients in whom the relative renal function deteriorates, relief of obstruction becomes surgically necessary and if this artifact can be removed. Supranormal function in an obstructed kidney is confusing and there is no consensus on how to manage these patients. There is no agreement if this is a true entity or an artifact. We wanted to address this issue by reporting our experience. METHODS: We reviewed all the consecutive cases from August 2000 to October 2001 who were studied in our center with the diagnosis of unilateral renal obstruction for confirmation or evaluation of DRF. All patients had MAG-3 studies that were interpreted by experienced nuclear medicine physicians. The DRF were measured within the first to second minute of the MAG-3 injection. Regions of interest were drawn by the imaging software and the images were corrected for background counts by drawing regions of interest 2 pixels away from the edge of the renal cortex. RESULTS: Fifty-seven patients were confirmed to be obstructed unilaterally; 41 (72%) patients had obstructive lesions in the left kidney and 16 (28%) in the right kidney. There was no case of supranormal DRF in the obstructed kidneys in our study. CONCLUSION: The supranormal renal function, as noted in some reports in the literature, was not seen in any patients at our institution. We believe that this entity is an artifact and can be avoided by using MAG-3 and projecting regions of interest by computer software; we plan to start analyzing multiple algorithms in phantoms with different ROI selection for background analysis.     

Epinephrine renal venography in severe inflammatory disease of the kidney

In a comparative study of the diagnostic value of epinephrine renal venography (ERV) and angiography in eight patients with severe inflammatory disease of the kidneys, the spectrum of abnormalities exhibited by ERV was more striking than the angiographic findings. Complete disorganization of the renal venous architecture with linear streaking of contrast agent is a sign of renal inflammatory disease. ERV is a useful adjunctive diagnostic procedure in cases of a nonfunctioning kidney.     

Selective renal venography in patients with primary renal disease and the nephrotic syndrome

Fifteen patients with primary renal disease and renal vein thrombosis who presented with the nephrotic syndrome were investigated venographically. In 46% of the patients the cavogram was normal. Selective renal venography is necessary in such patients because the course of patients with renal vein thrombosis and membranous glomerulonephritis is identical to that of patients with membranous glomerolonephritis alone. Eighty per cent of our patients had membranous glomerulonephritis; renal vein thrombosis is now thought to be secondary to this disease.     

Massive unilateral non-functioning hydronephrosis in horseshoe kidney.

The occurrence of non-function in one half of a horseshoe kidney resulting from hydronephrosis can, if unrecognized, create a serious surgical as well as medical problem. The anterior position of the ureter in relation to the isthmus, as well as strictures and accessory vessels increase the incidence of hydronephrosis, which if severe enough, can go on to non-function. The key diagnostic factor is the observation of the visualised side, which shows the characteristic malrotation of the calyces and the deviation of the long axis of the kidneys; these are associated with a mass effect on the obstructed side, with or without a 'crescent' sign. Five cases of this unusual occurrence are presented.     

Dilatation of the common bile duct secondary to a hydronephrotic kidney

Obstruction of the common bile duct secondary to hydronephrosis is uncommon. We observed common bile duct dilatation secondary to marked right hydronephrosis. Following nephrectomy the common bile duct returned to normal size, confirming the suspicion that the dilatation was due to extrinsic compression.     

Selective spermatic venography and varicocele embolization in men with circumaortic left renal veins

The presence of variant venous anatomy may increase the technical difficulty of percutaneous varicocele embolization. The authors review their experience performing venography of the left spermatic vein and varicocele embolization in 18 men with circumaortic left renal veins. Selective catheterization of the left spermatic vein was achieved in all but one patient, and all patients with positive venographic results underwent successful embolization. The site of the confluence of the left spermatic vein and the renal vein was variable and it was necessary to use jugular and femoral venous approaches to achieve selective left spermatic vein catheterization. Familiarity with anatomic variations associated with circumaortic renal veins and with embolization techniques from jugular and femoral venous routes facilitates percutaneous varicocele embolization in patients with this variant.     

Inferior caval venography in the assessment of renal carcinoma.

Inferior caval venography by a non-catheter technique was carried out in 30 cases of renal cell carcinoma. Occlusion of the renal vein was shown in 15 of these and occlusion of the inferior vena cava in a further three. Deformity of the vena cava by adjacent growth was found in nine instances. Renal arteriography was performed in 27 of these patients and the demonstration of the renal vein by this method has been compared with that of caval venography. The incidence of collateral veins on the arteriogram and the finding of impaired renal function as an index of renal vein occlusion has been discussed.